Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "pkt-line.h"
   3#include "run-command.h"
   4
   5char packet_buffer[LARGE_PACKET_MAX];
   6static const char *packet_trace_prefix = "git";
   7static struct trace_key trace_packet = TRACE_KEY_INIT(PACKET);
   8static struct trace_key trace_pack = TRACE_KEY_INIT(PACKFILE);
   9
  10void packet_trace_identity(const char *prog)
  11{
  12        packet_trace_prefix = xstrdup(prog);
  13}
  14
  15static const char *get_trace_prefix(void)
  16{
  17        return in_async() ? "sideband" : packet_trace_prefix;
  18}
  19
  20static int packet_trace_pack(const char *buf, unsigned int len, int sideband)
  21{
  22        if (!sideband) {
  23                trace_verbatim(&trace_pack, buf, len);
  24                return 1;
  25        } else if (len && *buf == '\1') {
  26                trace_verbatim(&trace_pack, buf + 1, len - 1);
  27                return 1;
  28        } else {
  29                /* it's another non-pack sideband */
  30                return 0;
  31        }
  32}
  33
  34static void packet_trace(const char *buf, unsigned int len, int write)
  35{
  36        int i;
  37        struct strbuf out;
  38        static int in_pack, sideband;
  39
  40        if (!trace_want(&trace_packet) && !trace_want(&trace_pack))
  41                return;
  42
  43        if (in_pack) {
  44                if (packet_trace_pack(buf, len, sideband))
  45                        return;
  46        } else if (starts_with(buf, "PACK") || starts_with(buf, "\1PACK")) {
  47                in_pack = 1;
  48                sideband = *buf == '\1';
  49                packet_trace_pack(buf, len, sideband);
  50
  51                /*
  52                 * Make a note in the human-readable trace that the pack data
  53                 * started.
  54                 */
  55                buf = "PACK ...";
  56                len = strlen(buf);
  57        }
  58
  59        if (!trace_want(&trace_packet))
  60                return;
  61
  62        /* +32 is just a guess for header + quoting */
  63        strbuf_init(&out, len+32);
  64
  65        strbuf_addf(&out, "packet: %12s%c ",
  66                    get_trace_prefix(), write ? '>' : '<');
  67
  68        /* XXX we should really handle printable utf8 */
  69        for (i = 0; i < len; i++) {
  70                /* suppress newlines */
  71                if (buf[i] == '\n')
  72                        continue;
  73                if (buf[i] >= 0x20 && buf[i] <= 0x7e)
  74                        strbuf_addch(&out, buf[i]);
  75                else
  76                        strbuf_addf(&out, "\\%o", buf[i]);
  77        }
  78
  79        strbuf_addch(&out, '\n');
  80        trace_strbuf(&trace_packet, &out);
  81        strbuf_release(&out);
  82}
  83
  84/*
  85 * If we buffered things up above (we don't, but we should),
  86 * we'd flush it here
  87 */
  88void packet_flush(int fd)
  89{
  90        packet_trace("0000", 4, 1);
  91        write_or_die(fd, "0000", 4);
  92}
  93
  94int packet_flush_gently(int fd)
  95{
  96        packet_trace("0000", 4, 1);
  97        if (write_in_full(fd, "0000", 4) == 4)
  98                return 0;
  99        return error("flush packet write failed");
 100}
 101
 102void packet_buf_flush(struct strbuf *buf)
 103{
 104        packet_trace("0000", 4, 1);
 105        strbuf_add(buf, "0000", 4);
 106}
 107
 108static void set_packet_header(char *buf, const int size)
 109{
 110        static char hexchar[] = "0123456789abcdef";
 111
 112        #define hex(a) (hexchar[(a) & 15])
 113        buf[0] = hex(size >> 12);
 114        buf[1] = hex(size >> 8);
 115        buf[2] = hex(size >> 4);
 116        buf[3] = hex(size);
 117        #undef hex
 118}
 119
 120static void format_packet(struct strbuf *out, const char *fmt, va_list args)
 121{
 122        size_t orig_len, n;
 123
 124        orig_len = out->len;
 125        strbuf_addstr(out, "0000");
 126        strbuf_vaddf(out, fmt, args);
 127        n = out->len - orig_len;
 128
 129        if (n > LARGE_PACKET_MAX)
 130                die("protocol error: impossibly long line");
 131
 132        set_packet_header(&out->buf[orig_len], n);
 133        packet_trace(out->buf + orig_len + 4, n - 4, 1);
 134}
 135
 136static int packet_write_fmt_1(int fd, int gently,
 137                              const char *fmt, va_list args)
 138{
 139        static struct strbuf buf = STRBUF_INIT;
 140        ssize_t count;
 141
 142        strbuf_reset(&buf);
 143        format_packet(&buf, fmt, args);
 144        count = write_in_full(fd, buf.buf, buf.len);
 145        if (count == buf.len)
 146                return 0;
 147
 148        if (!gently) {
 149                check_pipe(errno);
 150                die_errno("packet write with format failed");
 151        }
 152        return error("packet write with format failed");
 153}
 154
 155void packet_write_fmt(int fd, const char *fmt, ...)
 156{
 157        va_list args;
 158
 159        va_start(args, fmt);
 160        packet_write_fmt_1(fd, 0, fmt, args);
 161        va_end(args);
 162}
 163
 164int packet_write_fmt_gently(int fd, const char *fmt, ...)
 165{
 166        int status;
 167        va_list args;
 168
 169        va_start(args, fmt);
 170        status = packet_write_fmt_1(fd, 1, fmt, args);
 171        va_end(args);
 172        return status;
 173}
 174
 175static int packet_write_gently(const int fd_out, const char *buf, size_t size)
 176{
 177        static char packet_write_buffer[LARGE_PACKET_MAX];
 178        size_t packet_size;
 179
 180        if (size > sizeof(packet_write_buffer) - 4)
 181                return error("packet write failed - data exceeds max packet size");
 182
 183        packet_trace(buf, size, 1);
 184        packet_size = size + 4;
 185        set_packet_header(packet_write_buffer, packet_size);
 186        memcpy(packet_write_buffer + 4, buf, size);
 187        if (write_in_full(fd_out, packet_write_buffer, packet_size) == packet_size)
 188                return 0;
 189        return error("packet write failed");
 190}
 191
 192void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 193{
 194        va_list args;
 195
 196        va_start(args, fmt);
 197        format_packet(buf, fmt, args);
 198        va_end(args);
 199}
 200
 201int write_packetized_from_fd(int fd_in, int fd_out)
 202{
 203        static char buf[LARGE_PACKET_DATA_MAX];
 204        int err = 0;
 205        ssize_t bytes_to_write;
 206
 207        while (!err) {
 208                bytes_to_write = xread(fd_in, buf, sizeof(buf));
 209                if (bytes_to_write < 0)
 210                        return COPY_READ_ERROR;
 211                if (bytes_to_write == 0)
 212                        break;
 213                err = packet_write_gently(fd_out, buf, bytes_to_write);
 214        }
 215        if (!err)
 216                err = packet_flush_gently(fd_out);
 217        return err;
 218}
 219
 220int write_packetized_from_buf(const char *src_in, size_t len, int fd_out)
 221{
 222        int err = 0;
 223        size_t bytes_written = 0;
 224        size_t bytes_to_write;
 225
 226        while (!err) {
 227                if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)
 228                        bytes_to_write = LARGE_PACKET_DATA_MAX;
 229                else
 230                        bytes_to_write = len - bytes_written;
 231                if (bytes_to_write == 0)
 232                        break;
 233                err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
 234                bytes_written += bytes_to_write;
 235        }
 236        if (!err)
 237                err = packet_flush_gently(fd_out);
 238        return err;
 239}
 240
 241static int get_packet_data(int fd, char **src_buf, size_t *src_size,
 242                           void *dst, unsigned size, int options)
 243{
 244        ssize_t ret;
 245
 246        if (fd >= 0 && src_buf && *src_buf)
 247                die("BUG: multiple sources given to packet_read");
 248
 249        /* Read up to "size" bytes from our source, whatever it is. */
 250        if (src_buf && *src_buf) {
 251                ret = size < *src_size ? size : *src_size;
 252                memcpy(dst, *src_buf, ret);
 253                *src_buf += ret;
 254                *src_size -= ret;
 255        } else {
 256                ret = read_in_full(fd, dst, size);
 257                if (ret < 0)
 258                        die_errno("read error");
 259        }
 260
 261        /* And complain if we didn't get enough bytes to satisfy the read. */
 262        if (ret < size) {
 263                if (options & PACKET_READ_GENTLE_ON_EOF)
 264                        return -1;
 265
 266                die("The remote end hung up unexpectedly");
 267        }
 268
 269        return ret;
 270}
 271
 272static int packet_length(const char *linelen)
 273{
 274        int val = hex2chr(linelen);
 275        return (val < 0) ? val : (val << 8) | hex2chr(linelen + 2);
 276}
 277
 278int packet_read(int fd, char **src_buf, size_t *src_len,
 279                char *buffer, unsigned size, int options)
 280{
 281        int len, ret;
 282        char linelen[4];
 283
 284        ret = get_packet_data(fd, src_buf, src_len, linelen, 4, options);
 285        if (ret < 0)
 286                return ret;
 287        len = packet_length(linelen);
 288        if (len < 0)
 289                die("protocol error: bad line length character: %.4s", linelen);
 290        if (!len) {
 291                packet_trace("0000", 4, 0);
 292                return 0;
 293        }
 294        len -= 4;
 295        if (len >= size)
 296                die("protocol error: bad line length %d", len);
 297        ret = get_packet_data(fd, src_buf, src_len, buffer, len, options);
 298        if (ret < 0)
 299                return ret;
 300
 301        if ((options & PACKET_READ_CHOMP_NEWLINE) &&
 302            len && buffer[len-1] == '\n')
 303                len--;
 304
 305        buffer[len] = 0;
 306        packet_trace(buffer, len, 0);
 307        return len;
 308}
 309
 310static char *packet_read_line_generic(int fd,
 311                                      char **src, size_t *src_len,
 312                                      int *dst_len)
 313{
 314        int len = packet_read(fd, src, src_len,
 315                              packet_buffer, sizeof(packet_buffer),
 316                              PACKET_READ_CHOMP_NEWLINE);
 317        if (dst_len)
 318                *dst_len = len;
 319        return (len > 0) ? packet_buffer : NULL;
 320}
 321
 322char *packet_read_line(int fd, int *len_p)
 323{
 324        return packet_read_line_generic(fd, NULL, NULL, len_p);
 325}
 326
 327int packet_read_line_gently(int fd, int *dst_len, char **dst_line)
 328{
 329        int len = packet_read(fd, NULL, NULL,
 330                              packet_buffer, sizeof(packet_buffer),
 331                              PACKET_READ_CHOMP_NEWLINE|PACKET_READ_GENTLE_ON_EOF);
 332        if (dst_len)
 333                *dst_len = len;
 334        if (dst_line)
 335                *dst_line = (len > 0) ? packet_buffer : NULL;
 336        return len;
 337}
 338
 339char *packet_read_line_buf(char **src, size_t *src_len, int *dst_len)
 340{
 341        return packet_read_line_generic(-1, src, src_len, dst_len);
 342}
 343
 344ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out)
 345{
 346        int packet_len;
 347
 348        size_t orig_len = sb_out->len;
 349        size_t orig_alloc = sb_out->alloc;
 350
 351        for (;;) {
 352                strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
 353                packet_len = packet_read(fd_in, NULL, NULL,
 354                        /* strbuf_grow() above always allocates one extra byte to
 355                         * store a '\0' at the end of the string. packet_read()
 356                         * writes a '\0' extra byte at the end, too. Let it know
 357                         * that there is already room for the extra byte.
 358                         */
 359                        sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
 360                        PACKET_READ_GENTLE_ON_EOF);
 361                if (packet_len <= 0)
 362                        break;
 363                sb_out->len += packet_len;
 364        }
 365
 366        if (packet_len < 0) {
 367                if (orig_alloc == 0)
 368                        strbuf_release(sb_out);
 369                else
 370                        strbuf_setlen(sb_out, orig_len);
 371                return packet_len;
 372        }
 373        return sb_out->len - orig_len;
 374}